|MIT Encyclopedia of the Cognitive Sciences, MIT Press, Cambridge, Mass., 1998|
|by Javier DeFelipe|
|Instituto Cajal (CSIC), Avenida Dr. Arce, 37 (28002-Madrid, Spain)|
|Ph: (34-1) 585 4735; Fax: (34-1) 585 4754|
|reprinted with permission from the author|
|Santiago Ramón y Cajal (1852-1934) was one of the most outstanding
neuroscientists of all time. He was born in Petilla de Aragón,
a small village in the North of Spain. He studied medicine in the Faculty
of Medicine in Zaragoza. In 1883 Cajal was appointed to the chair
of Descriptive and General Anatomy at the University of Valencia. In 1887
he moved to the University of Barcelona where he was appointed to the chair
of Histology and Pathological Anatomy. Then Cajal moved, until his
retirement, to the University of Madrid where he was appointed to the chair
of Histology and Pathological Anatomy. Dr. Cajal received numerous
prizes, honorary degrees and distinctions, among the most important being
the Nobel Prize for Physiology or Medicine in 1906. To describe the
work of Cajal is rather a difficult task, because, unlike other great scientists,
he is not known for one discovery only, but for his many and important
contributions to our knowledge of the organization of the nervous system.
Those readers interested in his life should consult his autobiography (Cajal,
1917), where there is also a brief description of his main discoveries
and theoretical ideas.
The detailed study of the nervous system began in the middle of last century. Before Cajal's discoveries, very little was known about the neuronal elements of the nervous system, and the connections between its different parts were purely speculative. The origin of nerve fibers was a mystery, and it was speculated that they arose from the gray matter independently of the nerve cells (neurons). This lack of knowledge was due mainly to the fact that appropriate methods for visualizing neurons were not available; the early methods of staining only permitted the visualization of neuronal cell bodies, a small portion of their proximal processes, and some isolated and rather poorly-stained fibers. It was in 1873 when the method of Camillo Golgi (1843-1926) appeared; for the first time, neurons were readily observed in histological preparations with all their parts: soma, dendrites and axon. Furthermore, Golgi-stained cells displayed the finest morphological details with an extraordinary elegance, which led to the characterization and classification of neurons, as well as to the study of their possible connections. Due to this technical advance, Golgi shared the Nobel Prize with Cajal.
Cajal was not introduced to a scientific career under the direction of any scientist, as then usually occurred with most scientists, but rather he became a prominent neurohistologist on his own. The career of Cajal can be divided into three major phases (DeFelipe and Jones, 1991):
Cajal, S.R., 1909, 1910, Histologie du système nerveux de l'homme et des vertébrés. (Translated by L. Azoulay). Paris: Maloine. There is an English translation: Histology of the nervous system of man and vertebrates (translated by N. Swanson and L.W. Swanson), New York: Oxford University Press, 1995).
Cajal, S.R., 1913-1914, Estudios sobre la degeneración y regeneración del sistema nervioso. Madrid: Moya. There is an English translation: Degeneration and regeneration of the nervous system (translated and edited by Raoul M. May), London: Oxford University Press, 1928). Reprinted and edited with additional translations by DeFelipe, J. and E.G. Jones: Cajal's degeneration and regeneration of the nervous system. New York: Oxford University Press, 1991).
Cajal, S.R., 1917, Recuerdos de mi vida, Vol.2: Historia de mi labor científica. Madrid: Moya. There is an English translation: Recollections of my life (translated by E.H. Craigie with the assitence of J. Cano), Philadelphia: American Philosophical Society, 1937). Reprinted Cambridge, Mass.: MIT Press, 1989.